Thiruvananthapuram: The
Kerala water authority (
KWA) has decided to use extended aeration to get rid of yellow colour in
drinking water.
Complaints of yellow coloured water coming from pipes have come up from different parts of the city. KWA officials had said the phenomenon has been repeating every summer for the past 10 years.
Tests conducted by KWA in samples collected from different places have recently found that iron content was above normal in the treated water and it was the reason behind the yellow colour.
There is a change of colour in the water stored in Aruvikkara reservoir too and one can easily see that the water is slightly black in the surface. The same water, after going through the current mode of treatment, will become yellow in colour. KWA officials now suggest extended aeration to remove colour of water.
The KWA has hired two compressors that will be used to blow air into the raw water to increase air content. Senior officials of KWA said that the compressor will be used in raw water which is brought for treatment in plants at Vellayambalam and Aruvikkara.
“The iron content is high during summer. The parameters were within limit during the initial days when yellow colour was reported. However, the latest study found that the iron content was above the permissible limit. It was 0.6 mg/litre against the normal rate of 0.3 mg/litre,” said an official.
KWA officials feel that the trend happens during summer as the water remains idle at the reservoir. “Unlike other seasons, water remains idle during summer.
There is not much flow even through the pipeline. This helps in increase of iron content. This can be reduced by introducing aeration in the water using compressors,” the official said. The compressor will be used to blow air into the water.
The yellow colour was noticed in treated drinking water for around two weeks. The KWA initially ignored the issue as parameters were within limit. However, it decided to intensify treatment process after noticing considerable increase in iron content. Officials said that yellow colour has reduced in the past two days.
The KWA has hired the compressors on rent. It was planned to be use them on Monday, but was postponed due to harthal. It will start functioning from Tuesday. If found successful, KWA will purchase compressors which will be used during summers.
Sources in KWA said that issue of
yellow water is affecting quality of water not just in the city, but, also in other places.
